1. Field of the Invention
The present invention relates generally to displays, and particularly to a composite operational display unit of a vehicle instrument panel having plural operational displays.
2. Related Art
JP-A-10-91076 discloses a composite operational display unit having a first operational display and a second operational display. The second operational display is a transparent electroluminescent (EL) display and is disposed at a front side of the first operational display. However, in addition to the first and second operational displays, the composite operational display unit needs to have two drive circuits for respectively driving the first and second operational displays, while a mounting space of the composite operational display unit in a vehicle has been demanded to be reduced. Therefore, it is required to improve an efficiency in attachment and replacement of the first and second operational displays and the drive circuits in the display unit.